Water Quality is dictated by a host of factors, each playing a critical role in your pond’s ability to support a healthy, balanced ecosystem. The four principal water quality factors we look for when managing largemouth bass are Dissolved Oxygen, Water Clarity, Alkalinity, and Nutrient Levels.
Dissolved Oxygen is a measure of how much oxygen is dissolved in the water. Your ponds dissolved oxygen level, measured in milligrams per liter is one the most vital components of water quality to manage. Oxygen dissolves in water at exceptionally low rates. As a reference, our atmosphere, the air that we breathe, is around 20 percent oxygen, that is to say 200,000 milligrams per liter. A pond would be considered well oxygenated at anything above 8 mg/L. The growth of largemouth bass is hindered at levels below 4 mg/L. Levels below 1mg/L are considered lethal to largemouth bass and will only sustain the hardiest of fish. Luckily, dissolved oxygen is also one of the simplest water quality factors to manage. By adding a diffused aeration system to a pond, you can expect to see improved dissolved oxygen levels increased water quality, a higher usable volume of water in the pond for fish, and reduced algae growth. To begin measuring the dissolved oxygen in your pond, you just need a Dissolved Oxygen meter which can be purchased online through many outlets.
Water clarity has an enormous impact on the growth of largemouth bass and the overall production and quality of your pond. Largemouth bass are sight predators and in waters with a high visibility, bass will quickly consume their entire forage supply then be unable to continue feeding and growing. We like to manage the water clarity by promoting a phytoplankton bloom with the goal of achieving 18-24 inches of visibility. Phytoplankton is the beginning of the food chain and can increase overall carrying capacity within any lake 2 to 3 times. This bloom not only forms the base of the food chain, but it also helps to block sunlight from penetrating the water column to reach the pond’s bottom. This prevents unwanted vegetation growth. Water clarity can easily be measured using a Secchi Disk which is available for purchase online.
Alkalinity is determined by the amount of calcium carbonate in the water which acts as a buffer against rapid pH changes which can be lethal to fish. So, the variable we are really seeking to control with alkalinity is the pond’s pH. Bass can tolerate a wide range of pH levels from 4 to 10 because they can regulate their internal pH. However, this internal regulation requires time and energy. Shifting too dramatically can cause fish to succumb to pH changes before they have time to acclimate their bodies to the change. Even less dramatic daily shifts in pH can result in stunted growth rates due to the added stress and energy input required to maintain internal pH. Ideal alkalinity levels in a pond are between 50-150 parts per million. At these levels, the water is adequately buffered against pH changes. At levels below 20 ppm your water lacks natural minerals such as calcium that fish need to survive and grow. Luckily, alkalinity and pH problems are easy to amend with the application of agricultural lime. Alkalinity is little more difficult to measure and will require sending a water sample to a lab for analysis. This is something we can do for you anytime if you mail us a 16 ounce bottle of water from your pond.
Nutrient Levels dictate the plant and algae growth within a body of water as well as the growth of beneficial phytoplankton we mentioned earlier. The primary nutrients that influence plant growth in ponds and lakes are Nitrogen and Phosphorous. Everything else required for growth typically exists in abundance within most ponds and lakes. Because nitrogen and phosphorus are the two nutrients that are typically lacking and thus preventing growth, we call these our limiting factors. Adding even a little of either of these limiting factors to a pond which lacks them can cause a tremendous bloom of both good and bad vegetation. A nutrient rich pond that is shallow and clear enough for sunlight to reach the bottom is recipe for aquatic vegetation problems. Managing the levels and the timing of the addition of these two nutrients is essential to creating a healthy fishery. Nitrogen and Phosphorous testing kits are available online but the same water sample we use to measure alkalinity can be used to measure nutrient levels as well.